[ RadSafe ] Gulf War birth defects (Kang et al. study)

[Steven Dapra]

Feb. 2, 2007

         My thanks to Paul Charp for posting the citation to Kang that I 
had been asking James Salsman to provide.  (It is “Pregnancy outcomes among 
U.S. Gulf War veterans: a population-based survey of 30,000 
veterans.”  Kang H, Magee C, Mahan C, Lee K, Murphy F, Jackson L, Matanoski 
G. Ann Epidemiol. 2001 Oct;11(7):504-11.)

         Paul posted a small portion of the study and some of it sounded 
familiar, so I looked through my old DU e-mails.  Guess what I found?  In 
March 2006 Salsman and I were slugging it out over this study.  On March 28 
I put a posting on RADSAFE about the Kang et al. study, and between the 
asterisks I will reproduce the germane portion of it.  Then I will make a 
few additional comments.

*****

March 28 2006

[Kang, H., et al. (2001) in "Pregnancy  outcomes among US Gulf war 
veterans: a population-based survey of 30,000 veterans" Ann. Epidemiol. 11, 
504­511]

Concerning the incidence of birth defects it says:

" . . . male Gulf veterans reported infants with likely birth defect(s) at 
nearly twice the rate of controls (adjusted OR = 1.94; 95% CI = 1.37-2.74). 
. . . Female Gulf veterans were almost three times more likely to have a 
child with a likely birth defect than non-Gulf females, after adjusting for 
other factors (adjusted OR = 2.97; 95% CI = 1.47-5.99)." (p. 507) (The 
controls were non-Gulf veterans, as noted on p. 505.)

This study was based on data gathered in a 16-page questionnaire, that was 
re-sent to non-respondents at ten weeks, and again at six months. Further 
followup on non-respondents was conducted via telephone. "Veterans were 
asked to describe the birth defect, and to indicate cause and date for 
infant deaths. . . . All analyses of pregnancy outcomes were based on 
veteran self-reported outcome data and no validation of these reported 
outcomes with medical records was made." (p. 505)

In their Discussion (p. 507-510), the authors describe some additional 
analyses they conducted to try and filter out or account for possible 
reporting bias. They also state: "A third limitation of the study is that 
we were unable to evaluate specific defects, which may be etiologically 
different. Because of the dearth of documented information regarding 
specific exposures of particular veterans and the lack of knowledge on the 
human teratogenicity of most of the reported exposures, we were unable to 
evaluate which exposures might be associated with which outcomes." (p. 509)

In their Conclusions to their untitled abstract, the authors say, "This 
observation [of birth defects associated with Gulf War service] needs to be 
confirmed by a review of medical records to rule out possible reporting 
bias." (p. 504)

*****

Additional Comments:

         To reiterate, this was a self-reported study.

         Note that the authors say, “Because of the dearth of documented 
information regarding specific exposures of particular veterans and the 
lack of knowledge on the human teratogenicity of most of the reported 
exposures, we were unable to evaluate which exposures might be associated 
with which outcomes.”

         There may well have been an actual increase in birth 
defects.  Even if there was an increase, we do not know what caused the 
increase, and it certainly can not be automatically attributed to depleted 
uranium.

Steven Dapra
sjd at swcp.com

(James:  I located the Doyle and Ryan citation, so you need not provide it.)